Beijing's air - still safer to breathe than your car's exhaust: A racer protects his lungs as he bares his chest in the 3.5k Undies Run at Olympic Park in Beijing. In January, Beijing scored a 755 on the EPA's Air Quality Index, a 500-point scale in which 150 is "unhealthy" and above 300 is "hazardous."

Photo: ChinaFotoPress, ChinaFotoPress Via Getty Images

Beijing's air - still safer to breathe than your car's exhaust: A...

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A cold nose is healthy but this is ridiculous: A truffle-sniffing pooch owned by mushroom expert Fabian Sievers searches the snow for the valuable fungus in the woods near Hannover, Germany.

Photo: Lukas Schulze, AFP/Getty Images

A cold nose is healthy but this is ridiculous: A truffle-sniffing...

A cold nose is healthy but this is ridiculous: A truffle-sniffing... Photo-4248511.57474 - SFGate

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How do you say 'Fire!' in French? Ground Zero's Fall/Winter 2013-2014 ready-to-wear collection for Paris Fashion Week is smoking hot.

Photo: Martin Bureau, AFP/Getty Images

How do you say 'Fire!' in French? Ground Zero's Fall/Winter...

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Early birds share a romantic moment at sunrise on Rio's Copacabana beach.

Photo: Christophe Simon, AFP/Getty Images

Early birds share a romantic moment at sunrise on Rio's Copacabana...

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Shirt-optional practice, apparently: Pakistani Kushti wrestlers warm up before their daily training session at a gym in Lahore.

Steam rises from the Usiazha River on a frigid day near the Belarus village of Usiazha.

Photo: Viktor Drachev, AFP/Getty Images

Steam rises from the Usiazha River on a frigid day near the Belarus...

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Leave them alone and they'll come home … and stand at the barn bleating until you let them in out of the snow. (Basque village in Oquendo, Spain.)

Photo: Rafa Rivas, AFP/Getty Images

Leave them alone and they'll come home … and stand at the barn...

Leave them alone and they'll come home … and stand at the... Photo-4253267.57474 - SFGate

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Kansas gets socked again: With the temperature barely above freezing, snowflakes turn to water droplets on a car window in Hutchinson, Kan. The latest Midwest storm was expected to dump between eight and 24 inches of snow on the area.

Pouch-sized service pooches: Joe Hanson, a Vietnam veteran who suffers from post traumatic stress disorder, says his service dogs Star and Kira help keep him calm. He takes them everywhere on his motorcycle, including to the VA hospital in Gainesville, Fla., where he had an appointment Monday.